This invention relates to low alloy temper resistant tool steel and, more particularly, to such a steel which is especially well suited for use in making saw blades as well as a process for making the same.
Hitherto, the selection of steels available for use in providing the stock for making band saws has left much to be desired. On the one hand, the selection included high speed grades such as A.I.S.I. Type M2 which is relatively expensive because of the substantial amounts of alloying additions but which is generally tempered at about 1100.degree. F. to a hardness of about Rockwell C (Rc) 63 thereby providing a useful temperature range up to about 1100.degree. F., and, on the other hand, such high carbon grades as 1.25-1.3% carbon steel or A.I.S.I. Type 50100 containing 1-1.10% carbon and 0.50% chromium which is relatively inexpensive but which is normally tempered at about 350.degree. F. to Rc 63 and has a low useful temperature range. (Here and elsewhere throughout this application by percent is meant weight percent and the balance of each analysis unless otherwise stated is iron plus incidental impurities.) Alloys such as that set forth in U.S. Pat. No. 3,758,297 are not significantly less expensive than A.I.S.I. Type M2 because, inspite of the reduction in molybdenum to 1.3-1.6%, the tungsten content of 6-6.4% leaves the composition expensive when the maximum temperature anticipated in use will be less than about 600.degree. F.